1. Field of the Invention
This invention relates to a front steering axle, either drive or nondrive, having a low pivot angle and a negative offset to ground.
2. Description of the Prior Art
Classic front axles of the true or pseudo "Mac Pherson" type are characterized generally by the need to have either a large pivot angle in order to obtain a negative offset to ground (i.e., point of contact of pivot axis with the ground lying outside the median plane of the wheel) or a moderate pivot angle requiring a positive offset to ground.
It will be recalled that the pivot axis is an imaginary line passing, on the one hand, through the upper articulation of the strut to the body and, on the other, through the lower suspension ball-joint.
The great incline of the pivot axis alluded to above entails a high offset of wheel to stub axle. This notion can be visualized as the distance on the transverse axis passing through the stub axle between the intersection of this axis with the wheel plane and with the pivot axis.
A number of drawbacks flow from the preceding, such as that:
steering stiffness, and thus the stiffness of the connection leading to the steering wheel, are great and that,
the caster angle of such an axle varies during wide wheel-clearance and such variations are not negligeable, which had a bad influence on the reactions of the axle.
An axle assembly composed of two suspension triangles enables certain improvements to the preceding assembly to be obtained such as that:
the offset to ground may be made negative; and that
the ease of steering may be increased, since the carrying element does not move.
However, this type of assembly still presents the disadvantages of a relatively great pivot angle, to which are added the need to situate and affix the upper arm, which interferes with the engine compartment.